Hey... Don't feel too bad... Sounds EXACTLY like my first cross-bow shot... I hit a doe in the middle and it was a liver shot... With the angle it exited very low on her other side. I ran out of flashlights (lessoned learned) and had to wait till morning. Found her about 50 yards after I gave up... She had her rear munched on probably by 'yotes...

It is a shame, but at least she didn't suffer too much.